CLS
  SCREEN 9
  DO
  RANDOMIZE TIMER
  LINE (RND * 300 + 1, RND * 200 + 1)-(RND * 300 + 1, RND * 200 + 1), (RND * 12)
  LINE (RND * 300 + 1, RND * 200 + 1)-(RND * 300 + 1, RND * 200 + 1), (RND * 12), B
  LINE (RND * 300 + 1, RND * 200 + 1)-(RND * 300 + 1, RND * 200 + 1), (RND * 12), BF
  LOOP WHILE INKEY$ = ""